title: Direct quantitative assessment of the peripheral artery collateral circulation in patients undergoing angiography.
abstract: BACKGROUND
  Despite the fact that numerous studies have pursued the strategy of improving collateral function in patients with peripheral artery disease, there is currently no method available to quantify collateral arterial function of the lower limb.
  
  
  RESULTS
  Pressure-derived collateral flow index (CFIp, calculated as (occlusive pressure-central venous pressure)/(aortic pressure-central venous pressure); pressure values in mm Hg) of the left superficial femoral artery was obtained in patients undergoing elective coronary angiography using a combined pressure/Doppler wire (n=30). Distal occlusive pressure and toe oxygen saturation (Sao2) were measured for 5 minutes under resting conditions, followed by an exercise protocol (repetitive plantar-flexion movements in supine position; n=28). In all patients, balloon occlusion of the superficial femoral artery over 5 minutes was painless under resting conditions. CFIp increased during the first 3 minutes from 0.451±0.168 to 0.551±0.172 (P=0.0003), whereas Sao2 decreased from 98±2% to 93±7% (P=0.004). Maximal changes of Sao2 were inversely related to maximal CFIp (r(2)=0.33, P=0.003). During exercise, CFIp declined within 1 minute from 0.560±0.178 to 0.393±0.168 (P<0.0001) and reached its minimum after 2 minutes of exercise (0.347±0.176), whereas Sao2 declined to a minimum of 86±6% (P=0.002). Twenty-five patients (89%) experienced pain or cramps/tired muscles, whereas 3 (11%) remained symptom-free for an occlusion time of 10 minutes. CFIp values were positively related to the pain-free time span (r(2)=0.50, P=0.002).
  
  
  CONCLUSIONS
  Quantitatively assessed collateral arterial function at rest determined in the nonstenotic superficial femoral artery is sufficient to prevent ischemic symptoms during a total occlusion of 5 minutes. During exercise, there is a decline in CFIp that indicates a supply-demand mismatch via collaterals or, alternatively, a steal phenomenon. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. UNIQUE IDENTIFIER: NCT01742455.
authors.affiliation: Department of Cardiology, University Hospital, CH-3010 Bern, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Traupe
authors.forename: Jana
authors.initials: J
authors.lastname: Ortmann
authors.forename: Michael
authors.initials: M
authors.lastname: Stoller
authors.forename: Iris
authors.initials: I
authors.lastname: Baumgartner
authors.forename: Stefano F
authors.initials: SF
authors.lastname: de Marchi
authors.forename: Christian
authors.initials: C
authors.lastname: Seiler
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon; D001157:Arterial Occlusive Diseases / Q000097:blood / Q000503:physiopathology*; D021721:Balloon Occlusion / Q000009:adverse effects; D001794:Blood Pressure; D006328:Cardiac Catheterization; D003097:Collateral Circulation; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000628:therapy; D015444:Exercise / Q000502:physiology; D005260:Female; D005263:Femoral Artery / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D007511:Ischemia / Q000209:etiology / Q000503:physiopathology; D007866:Leg / Q000098:blood supply*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009120:Muscle Cramp / Q000209:etiology; D010100:Oxygen / Q000097:blood; D010146:Pain / Q000209:etiology; D058729:Peripheral Arterial Disease / Q000503:physiopathology; D011446:Prospective Studies; D012146:Rest / Q000502:physiology; D014034:Toes / Q000098:blood supply
chemical_list: D010100:Oxygen
keywords: angiogenesis; balloon occlusion; collateral circulation; peripheral artery disease